1. Field of Invention
The present invention relates to a table structure, and more particular to a foldable banquet table, which comprises a U-PVC tabletop for enhancing the rigidity of the tabletop in a runner-less manner.
2. Description of Related Arts
Conventional household furniture, such as dinning table, conference table or other types of work station, etc., in which its tabletop is made of wood or synthetic wood plank, has the advantageous of being substantively rigid and durable. In particularly, the one important feature of this kind of table which is integrally constructed is that the table is highly resistant to torsion. In addition, the leg frame can be directly coupled at the bottom side of the tabletop in order to secure the leg frame to the tabletop so as to enable the leg frame being folded between an unfolded position and a folded position in a stable manner. However, the use of wood plank in this kind of table has the following disadvantages: the material wood plank is heavy, inconvenience for storage and transportation, and has high consumption of wood materials.
Household furniture makes use of contemporary technologies to enable the use of light materials such as plastic for the tabletop. Accordingly, the plastic tabletop is made by blow mold injection that the plastic tabletop has a hollow structure. The use of plastic tabletop can reduce the weight and hence convenience for transportation, however, the rigidity and stability of the plastic made tabletop will be significantly decreased because the strength of this type of plastic tabletop is very weak. In addition, the plastic tabletop does not provide enough supportability and stabilization for the furniture. In other words, the loading force is not evenly distributed on each portion of the plastic tabletop so that the plastic tabletop will be deformed or even broken by the loading force.
In order to solve the problems and provide sufficient strength to the tabletop, an additional supporting structure made of metal has to be provided under the tabletop. Therefore, the cost of manufacture is highly increased and the convenience for transportation is lowered.
Accordingly, the supporting structure comprises two side runners respectively supported at two longitudinal side edge portions of the tabletop, wherein two longitudinal side channels are indented and pre-formed at the bottom side of the tabletop in order to receive the side runners respectively. In other words, the manufacturing process of the tabletop is relatively complicated to fit the side runners thereunder.
In addition, the leg frame cannot be directly coupled at the bottom side of the tabletop because of the hollow structure thereof. Therefore, the leg frame must be coupled between the side runners in order to fold between an unfolded position and a folded position. In other words, the leg frame and the tabletop do not provide an integral structure to provide protection against the force of torsion and load. This drawback in relation to the effect of torsion becomes prominent and uncovered when the table as a whole is being moved or when a relatively great external force is imposed onto the tabletop.
Since the tabletop is relatively long in size, the strength of the plastic tabletop is weak that the mid-portion of the plastic tabletop may be cracked easily due to the downward loading force. Therefore, the supporting structure further comprises a mid-runner is transversely mounted at the bottom side of the mid-portion of the tabletop and is extended between the side runners to enhance the strength of the plastic tabletop. In order to foldably attach the leg frame to the tabletop, the leg frame comprises a standing leg rotatably mounted between the side runners and a folding leg pivotally mounted between the standing leg and the mid-runner such that the standing leg is capable of pivotally folding under the tabletop. As a result, the mi-runner not only enhances the strength of the tabletop but also rigidly supports the leg frame in a foldable manner. In other words, the plastic tabletop must include the side runners and the mid-runner in order to form the banquet table.
However, the mid-runner restricts the pivotally attaching position of the folding leg. Since the mid-runner is transversely mounted at the middle of the tabletop, the folding leg must be long enough to pivotally extend from the standing leg to the mid-runner, which may weaken the strength of the folding leg. In addition, the folding leg must be extended from the mid-runner to the standing leg at an inclined manner so that the leg space at the bottom of the tabletop for the user will be limited when the leg frame is folded at folded position.
Furthermore, due to the position of the mid-runner, the tabletop cannot be modified to employ with a folding hinge at the mid-portion thereof for further overlappedly folding the tabletop in half to substantially reduce the size of the tabletop.